Ash discharge for underfeed stokers



Feb. 1s, 1941.

R. L. BEERS ASH DISCHARGE FOR UNDERFED s'roKERs Filed June 26. 1939 2 Sheets-Sheet l INVENTOR. BY ROYCE LBEERS ATTORNEYS Feb.. m w41. R L. BEERS 2,232,507

vASI-I DISCHARGE FOR UNDERFEED STOKERS Filed June 26. 1939 2 Sheets-Sheet 2 FI*G.2

i v nnunmuu'uunununmu I Qlnnnummunmnunnuunun {nnmnmumnnununnnun '.punnunnnnunnnnnnnncrmq N B3 B INVENTOR. ROYCE L.. BE ERS Mr/mu M443@ ATTORNEYS Patented Feb. 18,1941

UNITED STATES PATENT" OFFICE ASH DISCHARGE FOR UNDERFEED STGKERS Royce L. Beers, Birmingham, Mich., assigner to Detroit Stoker Company, Monroe, Mich., a corporation of Michigan Application June 26, 1939, Serial No. 281,301

7 Claims. (Cl. 110-38 The invention relates to automatic stokers for ally supported in bearings E. F are arcuate ash furnaces of that type comprising inclined longidischarge grates having their upper ends suptudinally reciprocating grate bars along which ported on the rocker bars D and their lower the fuel is fed and ash discharge grates conends connected by links G to crank arms H on nected to the lower ends of said bars and movable a normally stationary rockshaft I. Thus, when therewith. The reciprocatory grates are supn the rocker bar C is actuated the grates B will be ported at their opposite ends upon rockable memlongitudinally reciprocated, and the ash discharge bers and the lower rockable member' also supports grates F will be carried thereby, the lower ends the ash discharge grates. To facilitate assembly moving with the links G about the pivotal con- 10 and to permitof repair the grates must be readily nection H to the cranks H. It is to be under- 10 engageable with or disengageable from the rockstood that there are stationary grate bars B3, Figers and with certain constructions this is accomure 2, alternatingr with the movable grate bars plished by providing open slots in the grates per- B and the effect of the reciprocation of the latter mitting of vertical engagement with the rocker is to feed the fuel downward onto the grates F 16 bars on which they are supported. However, from the lower ends `of which the ash is dis- 15 where there is any obstruction to the feeding of charged. the fuel and the reciprocation of the grates, there It is usual to provide such furnaces with a is a tendency for the latter to lift out of engagechamber J beneath the grates which contains air ment with the supporting rocker, thereby beat more than atmospheric pressure, and the 20 coming inoperative. rocker bar D in addition to its function of sup- 20 It is one of the objects of the instant invenporting the grates B, forms an air seal for said tion to obtain a` construction which while perchamber. There is also a chamber K beneath mitting quick engagement or disengagement of the ash discharge grates F containing air at a the grates with the supporting rockers, also prolower pressure than that in the chamber J and vides for interlocking so as to prevent accidental supplied from the latter through a damper con- 25 disengagement. A further object is to obtain a trolled port L. Thus, there is always an upward construction with which the incandescent fuel current of air passing about the grates B and F, and ash supported on the ash discharge grates is which sufficiently cools the same to prevent burnkept out of contact with the furnace wall, so as ing out.

to avoid fusion thereto. With these and other To accomplish the primary object of my inven- 30 minor objects in View, the invention consists in tion I have constructed the rocker bar D and the the construction as hereinafter set forth. discharge grates F so as to form an interlocking In the drawings: but pivotal engagement with each other. To this Figure 1 is a transverse section through a porend the bars D are formed in short sections tion of a furnace provided with my improved adapted to be arranged in alignment with each 35 Stoker; other and together extending the full length of Figure 2 is a plan view thereof; the series of grates between the front and rear Figure 3 is a perspective view of the rocker or bridge wall of the furnace. Each bar D has a member, fuel grates and ash discharge grates web portion D with interrupted cylindrical pordetached; tions D2 at the lower end thereof for engage- 40 Figure 4 is an enlarged section similar'to Figment with the supporting bracket bearings E. ure 1, showing the manner of unlocking the These bearings have interrupted hooked portions grates from the rocker to permit disengagement E for pivotally engaging and interlocking 4with thereof; 4 the portions D2. The spaces D3 intermediate said Figure 5 is an elevation of the tuyre for coportions D2 permit of aligning the latter with the 45 operating with the ash discharge grates. hooked bearings E', after which an axial move- In general construction the Stoker to which my ment of the member D will complete the en` improvements are applied comprises a central gagement. In this way the members D may be retort A and inclined grate bars B extending successively engaged with the bracket bearings therefrom toward opposite sides of the furnace, `E to extend from one end to the other of the 50 only one side being illustrated. The bars B are series. supported `at their upper ends upon rocker bars The members D* are further provi-ded at their C which are actuated by suitable mechanism upper ends with interrupted cylindrical portions (not shown). At their lower ends these bars also D4 and in the spaces between these portions l rest upon rocker hars `D which in turn are pivotcylindricalportions D5 of smaller diameter. The 5l ciw grate bars B which are hollow and preferably formed of complementary channeled sections have at their lower ends semi-cylindrical bearings B which may be directly engaged with the bars D normally resting on the portions D5 thereof. The grate bars F are formed at their upper ends with hooked segments F of an axial length less than the width of said bars, which segments extend circumferentially more than 180 and are of a radius for fitting the portions D4 and pivotally interlocking therewith. These hooked portions cannot, therefore, be directly engaged with the portions D4, but by first registering the portions F with the smaller diameter portions D5 they may be engaged therewith, after which an axial movement will engage them with the portions D4. In this way, the members F are locked to the bars D so as to be held from accidental disengagement, while at the same time permitting a free pivotal action, The members F are of a width greater than the width of the grate bars B, so that they will overlap a plurality of said bars. The hooked portions F are, however, substantially the width of the stationary grate bars and the portions F2 on opposite sides of said hooked portions will overlap the movable grate bars substantially one-half their width. These overlapping portions F2 are fashioned to engage external cylindrical segments B2 on the grate bars B and in normal position will prevent the lifting of said grate bars out of engagement with the rocker bars D. If, however, the members F are drawn downward by the rocking of the cranks I-I so as to swing about the axis of the portions D4 and D5 of the bars D, this will place them in a position to clear the segments B2 to permit the lifting oif of the bars B.

To prevent the molten ash and clinker from adhering to the side wall of the furnace, I have provided a cooled member arranged opposite the lower end of the ash grates F and between which and said grates the ash is discharged into the chamber K. As shown in Figure 1, this member comprises a series of tuyres M secured in the furnace wall and projecting outward therefrom. As specifically illustrated, a channel beam N is placed in a recess in the furnace wall, said beam having a rib N depending from its upper flange and a series of lugs N2 projecting forward from its web portion having aligned apertures therein. Each tuyre has an inclined top portion M and a central rearwardly extending web poion M2 provided with a hood M3 for engaging with the rib N. This web is also apertured in alignment with the apertures in the lugs N2 for the insertion of a holding rod N3 which may be inserted from the front of the furnace to lock all of the tuyres to the channel beam. Thus, air from the chamber K will pass upward around and between the tuyres M to cool the same, as well as to support combustion of the partially consumed fuel above the grates and tuyres.

The parts being constructed and assembled as abo-ve described, they will normally operate as follows. The rocking of the rocker bars C will impart longitudinal movement to the grate bars B, which in turn will actuate the rocker bars D and ash discharge grates F. The lower ends of the latter will swing about the center H', the shaft I and cranks I-I being normally stationary. Inasmuch as the hooked portion F of each ash discharge grate F is in engagement with the portion D4 of the rocker bar D, this will prevent any lifting of said member F out of engagement withthe rocker. Also, as the portions F2 of the member F extend over the arcuate portions B2 of the grate bars B they will prevent the lifting of the latter bars.

If at any time it is necessary to remove any of the grate bars B or ash discharge grates F this may be accomplished by manually rotating the shaft I to turn the cranks H downward. This, through the medium of the links G, will swing the ash discharge grates F downward to a position where the portions F' will clear the portions B2 of the grate bars B. The latter bars may then be lifted off from the rocker bars D and C. The grate F may be disengaged by disconnecting the link G therefrom, after which it may be moved axially off from the portion D* and onto the portion D5 of the rocker bar D, As the diameter of the portion D5 is less than that of the opening into the hook, the latter may be lifted out of engagement.

In the normal functioning of the apparatus the downward movement of the ash discharge grates F will effect the discharge of fine ash between the same and the tuyres M. It will also have the effect of breaking up the clinker, inasmuch as the upper surface of the grate F is toothed. If, however, any clinker is formed which cannot be discharged between the grate F and the tuyre M, the rockshaft I may be manually operated to swing the grate downward about the portion DA of the rocker bar D, thereby enlarging the space between the grate and the tuyre.

What I claim as my invention is:

l. In a furnace including replaceable reciprocatory grate bars and a rocker member for .v supportingy said grate bars, of means for nor- 2. In a furnace including replaceable reciprocatory grate bars, a support and a rockable member intermediate said support and grate bars, of means for normally restraining vertical displacement of said grate bars with respect to said rocker member and support while permitting of assembly and disassembly of such parts, said means comprising segmental cylindrical bearings on certain of `said grate bars and on said support, said bearings having entrant slots of lesser width than the internal diameter thereof, and inter-i rupted pivots on said rocker member axially alignable and subsequently engageable with their corresponding bearings b-y a movement relative thereto normal to the axis while said bearings are in registration with interruptions.

3. -In a furnace including replaceable reciprocatory fuel supporting grate bars, aligned ash discharge members and a rocker member for supporting the adjacent ends of said aligned grate bars and ash discharge members, of means for normally restraining vertical displacement of said grate bars with respect to said rocker member while permitting assembly and disassembly of such parts comprising an interlocking pivotal connection between said ash discharge member and rocker including a segmental cylindrical bearing on the one and an interrupted vpivot on the other, said bearing having an entrant slot of lesser width than the diameter of the pivot and being engageable by a movement transverse to the axis and an axial movement of one with respect to the other, a pivotal connection between said grate bar and rocker Vengageable by a relative movement transverse to the axis, and means on said ash discharge member overlapping a portion of said grate member to restrain the same from disengagement in the normal relation of these parts, said means being disengaged by an abnormal rotation of said ash discharge member about its pivotal connection with said rocker.

4. In a furnace including replaceable reciprocatory grate bars, a support and a rockable member intermediate said support and grate bars, of means for normally restraining vertical displacement of said grate bars with respect to said rocker member and support while permitting assembly and disassembly of such parts, said means comprising bearings -on certain of said grate bars and on said support having entrance slots therein of lesser width than the internal diameter of the bearings, and interrupted pivot portions on said rocker member permitting of relative movement normal to the axis thereof int-o axial alignment with said bearings When the latter are registered with said interruptions and also engagement with said bearings by a relative axial movement.

5, In a furnace including replaceable reciprocatory grate bars and a rocker member for supporting said grate bars, of means for normally restraining vertical displacement of said grate bars with respect to said rocker member while permitting of assembly and disassembly of the same, said means comprising alternate pivot portions of different radii on the upper end of said rocker member, bearings on certain of said grate bars corresponding to the pivot portions of larger radius and having entrance slots of lesser width permitting movement normal to the axis over the pivot portions of smaller radius into axial alignment with the larger radius portions and axial movement into engagement therewith, bearings on alternate grate bars corresponding to the pivot portions of smaller radius and engageable therewith by a movement normal to the axis, and means on the first mentioned grate bars normally restraining displacement of the second mentioned grate bars but permitting disengagement thereof when said rst mentioned grate bars are swung about their pivots to an abnormal position.

6. In a furnace including replaceable reciprocatory fuel supporting grate bars, aligned ash discharge grate bars and a rocker member for supporting the adjacent ends of said aligned grate bars, of means for normally restraining vertical displacement of said grate bars with respect to said rocker member while permitting assembly and disassembly of the same, said means comprising alternate pivot portions of different radii on the upper end of said rocker member, bearings on said ash discharge grate bars corresponding to the pivot portions of larger radius and having entrance slots of lesser width permitting movement normal to the axis over the pivot portions of smaller radius into axial alignment with the larger radius portions and axial movement into engagement therewith, bearings on said fuel supporting grate bars corresponding to the pivot portions of smaller radius and engageable therewith by a movement normal to the axis, and means on the first mentioned grate bars which in normal position restrains displacement of the second mentioned grate bars but permits disengagement thereof(` when said rst mentioned grate bars are swung about their pivots to an abnormal position.

7. In a furnace including replaceable reciprocatory fuel supporting grate bars and aligned ash discharge grate bars, of a series of aligned transversely extending rocker members for supporting the adjacent ends of said grate bars, a series of spaced stationary bearings for supporting said rocker members each bearing having an entrance slot of lesser Width than the internal diameter of the bearing, said rocker members being formed with interrupted pivot portions at their lower ends successively engageable with said bearings by a movement normal to the axis and axial movement relative thereto, each of said rocker members also having at its upper end alternate pivot portions of different radii, a bearing on` each of said ash discharge grate bars corresponding to the pivot portion of larger radius and provided with an entrance slot of lesser Width, said bearings being engageable with said rocker member by a movement normal to the axis over the pivot portion of smaller radius and axial movement onto the pivot portion of larger radius', a bearing on each of said fuel supporting grate bars engageable with said pivot portion of smaller radius by a movement normal to the axis thereof, and means on each ash discharge grate bar normally overlapping a portion on the adjacent fuel supporting grate bar to hold the same from vertical displacement, said overlapping means being disengageable by rotation of said ash discharge grate bar about its pivot to an abnormal position.

ROYCE L. BEERS. 

